If you want to understand "Nerf" better here you go:
"Nerfing" does not make the game safer or anything like that... it robs the power out of a thing.
Take a wooden baseball bat and take a solid swing into a normal baseball and you can watch the ball fly a grand arch out into the bleechers, then...
Take a NERF bat (this is an actual product sold in toy stores) and a nerf ball and try the same thing, and the ball barely sails across the room.
Safer may apply in the real world, but then you factor in that we are playing a video game and no one can possibly get more than their feelings hurt. In game it just means weaker, or fake, or even "not at all what is was."
I "Nerf baseball bat" can be called a "bat" I suppose, but it still is not a baseball bat. It's nerf (foam).
So if you cheapen down and take the heart and soul out of a thing, oh lets say the way Jedi has been gutted and made weak and impotent, and then you think of swinging a foam bat at a brick wall, and VOILA! You understand the meaning and etymology (history) of the word: NERF.
I hate my Jedi now... Oh pardon me, I don't mean "Jedi", I mean "Nerf Brand "'Jedi-like Action Figure'". Play a Jedi today and that's what Nerf really means.